German Citizenship
My mother moved to US in the early 50s. She was born in Germany to German mother and father. Her Father was a soldier and killed in WWII, her Mother came to US with assistance from father’s half sister. My mother naturalized in US at age of 20 (in 1963), my understanding of that she did not lose her citizenship at that time because she was technically a minor. She married my American father in 1965 and I was born in 1967. She lost citizenship at marriage and I would qualify for reinstatement of citizenship with STAG. My question is how to prove citizen of my grandfather. He was born out of wedlock and adopted by a German couple. His birth mother was also German, but now much is known about these details. His mother had at least two children by different men, because the half-sister was moved to San Fran and later sponsored his widow, my grandmother. As an adopted child, do I look toward his adoptive parents for citizenship proof or try to figure out who his mother was. Would his death certificate show citizenship?